The present invention relates to a fixing structure of a relay connector capable of easily providing a board on a relay connector for electrically connecting a core conductor of a coaxial connector to a terminal electrode which is provided on a surface of the board, and for electrically connecting a shell ground (GND) of the coaxial connector to a GND electrode which is provided on a back surface of the board, for the purpose of inspecting the board.
In designing and producing a high frequency circuit board or the like, it is necessary to evaluate its performance in a course of designing. Therefore, by electrically connecting a core conductor of a coaxial connector to a terminal electrode which is provided at an end of a surface of the board, and by electrically connecting a shell GND of the coaxial connector to a GND electrode which is provided at an end of a back surface of the board, evaluation of the performance is achieved on the basis of a high frequency signal which is obtained from the terminal electrode. On this occasion, in case where a structure for electrically connecting the core conductor of the coaxial connector to the terminal electrode and electrically connecting the shell GND of the coaxial connector to the GND electrode is formed by soldering work, the work is complicated. Moreover, a work for removing the coaxial connector which has been soldered and fixed, from the board is also complicated. In view of the above, a related-art relay connector in which the coaxial connector can be attached to the board, without soldering has been already proposed (refer to JP-A-2008-171801).
The related-art relay connector disclosed in JP-A-2008-171801 will be briefly described referring to FIGS. 13A to 15. FIGS. 13A, 13B and 13C are views showing an outer appearance of the related-art relay connector. FIG. 13A is a side view, FIG. 13B is a plan view, and FIG. 13C is a front view. FIG. 14 is a sectional view as seen from arrow marks A-A in FIG. 13B. FIG. 15 is an exploded perspective view of the relay connector as shown in FIGS. 13A to 13C. In the related-art relay connector as shown in FIGS. 13A to 15, a through hole 20a is provided in a main block 20 formed of conductive material, a dielectric member 22b projected from a shell GND 22a of a coaxial connector (an SMA connector, for example) 22 is inserted into the through hole 20a from a back surface, the shell GND 22a is fixed with screws to the back surface to be electrically connected, and further, a core conductor 22c which has been exposed by stripping off the dielectric member 22b is projected from a front surface of the main block 20. On this occasion, an end surface of the dielectric member 22b is at a substantially same position as the front surface of the main block 20 or at a slightly retreated position from the front surface. Moreover, an axial direction in which the core conductor 22c is projected is perpendicular to the front surface of the main block 20. Guide pins 24, 24 are uprightly provided in the main block 20 in parallel with the front surface of the main block 20. A GND block 26 formed of conductive material is provided with guide holes 26a, 26a into which the guide pins 24, 24 are inserted. By detachably inserting the guide pins 24, 24 into these guide holes 26a, 26a, the GND block 26 can relatively move with respect to the main block 20 in sliding contact with each other, in a linear direction parallel to the front surface of the main block 20. Further, the GND block 26 is provided with a board rest part 26b so as to be opposed to the core conductor 22c in such a manner that the board rest part 26b can move in a direction of approaching or separating from the core conductor 22c by the relative movement.
Further, moving range regulating screws 32, 32 are passed through moving range regulating through holes 30a, 30a which are formed in a vertical direction in an operating member 30, so as to move within a determined range in an axial direction. Then, distal ends of the moving range regulating screws 32, 32 are screwed into the main block 20 at an opposite side to a position where the GND block 26 is provided with respect to the core conductor 22c, and erected, in such a manner that the operating member 30 can relatively move in a direction of approaching or separating from the main block 20 within a determined range. On this occasion, a direction of the GND block 26 approaching or separating from the core conductor 22c and a direction of the operating member 30 approaching or separating from the main block are parallel to each other. In addition, elastic springs 34, 34 as elastic members are provided in a contracted state between the operating member 30 and the main block 20, whereby the operating member 30 is elastically urged in a direction of separating from the main block 20. Still further, the operating member 30 and the GND block 26 are connected to each other by means of connecting members 38, 38 with connecting pins 36, 36. These connecting members 38, 38 allow the GND block 26 to move in a direction of approaching or separating with respect to the core conductor 22c in association with the movement of the operating member 30 in the approaching or separating direction. Still further, a leaf spring 40 having conductivity is fixed to the GND block 26 with small screws. The leaf spring 40 is slidably provided in elastic contact with the main block 20, and electrically connected thereto. It is to be noted that a lateral width W of the related-art relay connector is set to be 12.7 mm, for example, which is equal to the lateral width of the shell GND 22a of the coaxial connector 22.
In the related-art relay connector disclosed in JP-A-2008-171801, the board is inserted between the core conductor 22c and the board rest part 26b, by enlarging a distance between the core conductor 22c and the board rest part 26b by the relative movement of the main block 20 and the GND block 26, and the board can be clamped between the core conductor 22c and the board rest part 26b by reducing the distance between them by the relative movement. Then, the core conductor 22c of the coaxial connector 22 is brought into contact with a terminal electrode provided on a surface of the board to be electrically connected, and a GND electrode provided on a back surface of the board is electrically connected to the shell GND 22a of the coaxial connector 22 by way of the GND block 26 having the board rest part 26b and the main block 20. In this manner, it is possible to easily electrically connect the board to the coaxial connector 22. Moreover, it is possible to easily detach the board which has been inserted between the core conductor 22c and the board rest part 26b, by enlarging the distance between them by the relative movement. When the operating member 30 is pressed to move toward the main block 20 against elastic forces of the elastic members 34, 34, the board rest part 26b of the GND block 26 which is connected to the operating member 30 by means of the connecting members 38, 38 relatively moves in a direction of separating from the core conductor 22c, and the distance between the core conductor 22c and the board rest part 26b is enlarged, whereby the board can be inserted between them. Further, when the pressure on the operating member is released, the board can be clamped between the core conductor 22c and the board rest part 26b with the elastic forces. The related-art relay connector disclosed in JP-A-2008-171801 is fixed to a base seat with screws or the like in a position where it corresponds to an outer shape of the board and opposes to the terminal electrode 12 arranged on the board.
Further, a related-art structure of a relay connector in which the related art disclosed in JP-A-2008-171801 is further improved, has been proposed in Japanese Patent Application No. 2008-296620. In this related-art structure, the GND block is relatively moved with respect to the main block, and the distance between the core conductor and the board rest part is enlarged or reduced, thereby to insert and clamp the board between them, in the same manner as the related art disclosed in JP-A-2008-171801. However, in the related-art structure in Japanese Patent Application No. 2008-296620, operation of the operating member is more reliably transmitted to the GND block by means of the connecting members. Moreover, the relay connector is mounted on a slide rail which is longer in a projecting direction of the core conductor in such a manner that a position of the relay connector can be changed in a longitudinal direction of the slide rail, by regulating movement of the slide rail in the longitudinal direction thereof by an elastic force of a spring, and at the same time, by applying a larger force than the regulating force by the elastic force of the spring. Still further, a related-art relay connector in which a spark plug type connector is used as the coaxial connector, instead of an SMA type connector, has been proposed in Japanese Patent Application No. 2009-016602.
In the related art for fixing the relay connector disclosed in JP-A-2008-171801 to the base seat, there is no problem in providing the board on the relay connector, in case where the board has a rectangular shape, and the terminal electrodes are arranged at one side of the board or at two adjacent sides. However, in case where the terminal electrodes are arranged at two sides at both ends of the board opposed to each other, an interval at which the relay connector is to be provided is fixed, and the board must be exactly inserted between them. This work is very complicated. Further, in case where the terminal electrodes are arranged at all the four sides, it is impossible to correctly provide the board on the relay connector. Moreover, in the related art in Japanese Patent Application No. 2008-296620, the relay connector is allowed to move in the longitudinal direction of the slide rail, and therefore, even though the terminal electrodes are arranged at the four sides of the board, it is possible to correctly provide the relay connector by moving it so as to approach or separate from the board, after the board has been appropriately provided. However, because the position of the relay connector in the longitudinal direction of the slide rail is regulated by the elastic force of the spring, the force for regulating the position becomes short, in case where easy movement in the longitudinal direction is intended. Therefore, there is such anxiety that the relay connector is displaced, when a force for pulling a coaxial cable which is connected to the relay connector is exerted. In contrast, in case where the elastic force of the spring for regulating the position is increased, there occurs such inconvenience that the movement in the longitudinal direction cannot be smoothly achieved.